ul,li{
  padding: 0;
  list-style: none;
  margin: 0;
}
.box{
  margin-left: 300px;
  width: 450px;
  border: solid;
  overflow: hidden;

  display: flex;
  flex-wrap: nowrap;
  position: relative;

  .next,.pre{
    border: none;
    position: absolute;
    top:0;
    bottom: 0;
    width: 50px;
    display: flex;
    justify-content: center;
    align-items: center;
    background: rgba(0,0,0,.2);
    color: white;
    font-size: 30px;
    font-weight: bold;
    &:hover{
      background: rgba(0,0,0,.5);
      cursor: pointer;
    }
  }
  .next{
    right: 0;
  }
  .pre{
    left: 0;
  }

  ul{
    display: flex;
    flex-wrap: nowrap;
    // border: solid;
    // margin-left: -150*7px;
    transition: 200ms;
    li{
      width: 150px;
      height: 150px;
      img{
        width: 100%;
      }
    }
  }

}